posted on Aug, 14 2014 @ 12:59 PM
a reply to: wildespace
I'm very much looking forward to RGB images of the comet.
Any RGB images will not be the same thing as taking an RGB image on Earth, they will be spectral reflectance lines of specific elements.
A NAC image available today:
Taken on 7 August 2014, from a distance of 104 kilometres through the orange filter of the OSIRIS narrow-angle camera. They are separated by 17
minutes and the exposure time is 138 milliseconds.
With the orange filter they may be looking for pyroxene reflectance spectra.
SYSTEMATICS OF VESTOID REFLECTANCE SPECTRA BY 600-AND 650-nm BANDS.
By using different filters, and examining the spectra, they can further pin down the most likely materials by comparing the expected spectral lines in
each band with those observed, for each element.
Good to see they are giving the exposure time too. 0.138 sec may seem like a short exposure time, but given the sensitivity of the instruments, they
are likely still looking at some very weak, and 'thin' emissions, not naked eye visible IMO.